1. Field of the Invention
The present invention relates to a radiation sensor and a radiation image detection apparatus.
2. Description of the Related Art
In the field of medicine, use is being made of a radiation sensor which irradiates a human body with radiation such as X-ray, detects the intensity of the radiation that has penetrated the human body, and thereby detects the images of the inside of the human body. One type of such a radiation sensor is a system which first enters radiation that has transmitted into the human body, into a phosphor to thereby convert the radiation into visible light, converting this visible light into electrical signals, and then extracting the electrical signals to the outside.
As such a radiation sensor, for example, there is known a radiation sensor in which a shock-resistant phosphor layer composed of a polymer binder and a phosphor that is sensitive to radiation, such as gadolinium oxysulfide; an upper electrode; a lower electrode; and a shock-resistant substrate which is disposed between the upper and lower electrodes, and has an organic photoelectric conversion layer that absorbs the light emitted by the radiation incident to the phosphor layer to convert the light to charges, and a charge detection layer that includes a storage capacitor and a thin film transistor unit for reading the charges generated in the organic photoelectric conversion layer from each of the pixels for image detection (see Japanese Patent Application Laid-Open (JP-A) No. 2004-172375). Furthermore, since a thin film transistor which has an oxide semiconductor active layer containing zinc oxide, may be formed into a film at low temperature, an insulating substrate having flexibility, such as a plastic plate or a plastic film, may be used (see JP-A No. 2006-165530).
The radiation sensors described above have a flexible substrate that supports a phosphor layer and a shock-resistant substrate having a charge detection layer; however, the organic photoelectric conversion layer still lacks flexibility, and when the radiation sensors are bent, the image detecting performance may undergo deterioration.